It may all be true but it's not like poker works. As many pointed out, in poker you play against the other players, not the house. The house has a fixed rake which is actually pretty low in online games.
I don't consider myself a pro player and i don't intend to make a fortune playing online poker but in the last 4 months i have been playing my $50 investment turned into $200. I can't make a living with that but it sure beats playing WoW and losing $15 per month.
The trick is to never overplay your bankroll. I didn't make $150 with one lucky gamble on a $50 game. I made it by playing about 300 games. I lost some, sometimes 2 weeks in a row but in the long run good play will net you money.
Never play money that what you can't afford to lose. It's as simple as that.